Intervertebral discs function to stabilize the spine and to distribute forces between vertebral bodies. A normal disc includes a gelatinous nucleus pulposus, an annulus fibrosis and two vertebral end plates. The nucleus pulposus is surrounded and confined by the annulus fibrosis.
Degenerated discs are a significant source of spine-related pain. As people age, the nucleus pulposus begins to dehydrate. Dehydrated disc have a very limited ability to absorb shock and are a significant source of spine-related pain. In addition, the annulus fibrosis may tear due to an injury or the aging process allowing the nucleus pulposus to extrude through the tear. This condition is known as disc herniation. It is very common for the herniated disc to press against spinal nerves located near the posterior side of each disc all along the spine, causing radiating pain, numbness, tingling, and diminished strength and/or range of motion. In addition, the contact of the inner nuclear gel, which contains inflammatory proteins, with a nerve can also cause significant pain.
Amongst sufferers of chronic pain, spine-related problems constitute the bulk of such complaints. Spinal pain has been estimated to exist in as much as 66% of the general population. Beyond the substantial discomfort that back pain inflicts upon individuals, spine-related pain also incurs heavy societal costs. For example, as many as one million spine surgeries, and as many as five million interventional procedures, are estimated to be performed in the United States each year. Well beyond the purely medical and psychological burdens imposed by such procedures, the subsequent social costs related to productivity, disability compensation and lost taxes are substantial.
Although procedures for treating intervertebral disc injuries are known, there is still a need in the art for improved compositions and methods for treatment of such injuries.